HC2VPP-43: support for multiple DHCP servers for relay

Depends on https://gerrit.fd.io/r/#/c/5515/

Change-Id: I76d1b37b9d9e866fc97f3cc35c1ac01e48b0ab57
Signed-off-by: Marek Gradzki <mgradzki@cisco.com>

10 files changed, 165 insertions, 60 deletions

diff --git a/dhcp/dhcp-impl/src/main/java/io/fd/hc2vpp/dhcp/read/DhcpReaderFactory.java b/dhcp/dhcp-impl/src/main/java/io/fd/hc2vpp/dhcp/read/DhcpReaderFactory.java
index db719061b..2f71866d3 100644
--- a/dhcp/dhcp-impl/src/main/java/io/fd/hc2vpp/dhcp/read/DhcpReaderFactory.java
+++ b/dhcp/dhcp-impl/src/main/java/io/fd/hc2vpp/dhcp/read/DhcpReaderFactory.java
@@ -16,6 +16,7 @@
 
 package io.fd.hc2vpp.dhcp.read;
 
+import com.google.common.collect.ImmutableSet;
 import com.google.inject.Inject;
 import io.fd.honeycomb.translate.impl.read.GenericInitListReader;
 import io.fd.honeycomb.translate.read.ReaderFactory;
@@ -27,6 +28,7 @@ import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.dhcp
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.dhcp.rev170315.dhcp.attributes.Relays;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.dhcp.rev170315.dhcp.attributes.RelaysBuilder;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.dhcp.rev170315.dhcp.attributes.relays.Relay;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.dhcp.rev170315.relay.attributes.Server;
 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
 
 /**
@@ -45,6 +47,9 @@ public final class DhcpReaderFactory implements ReaderFactory {
     public void init(@Nonnull final ModifiableReaderRegistryBuilder registry) {
         registry.addStructuralReader(DHCP_ID, DhcpBuilder.class);
         registry.addStructuralReader(RELAYS_ID, RelaysBuilder.class);
-        registry.add(new GenericInitListReader<>(RELAY_ID, new io.fd.hc2vpp.dhcp.read.DhcpRelayCustomizer(vppApi)));
+        registry.subtreeAdd(
+            ImmutableSet.of(InstanceIdentifier.create(Relay.class).child(Server.class)),
+            new GenericInitListReader<>(RELAY_ID, new io.fd.hc2vpp.dhcp.read.DhcpRelayCustomizer(vppApi))
+        );
     }
 }
diff --git a/dhcp/dhcp-impl/src/main/java/io/fd/hc2vpp/dhcp/read/DhcpRelayCustomizer.java b/dhcp/dhcp-impl/src/main/java/io/fd/hc2vpp/dhcp/read/DhcpRelayCustomizer.java
index db7e7141c..875b93933 100644
--- a/dhcp/dhcp-impl/src/main/java/io/fd/hc2vpp/dhcp/read/DhcpRelayCustomizer.java
+++ b/dhcp/dhcp-impl/src/main/java/io/fd/hc2vpp/dhcp/read/DhcpRelayCustomizer.java
@@ -35,6 +35,7 @@ import io.fd.vpp.jvpp.core.dto.DhcpProxyDetails;
 import io.fd.vpp.jvpp.core.dto.DhcpProxyDetailsReplyDump;
 import io.fd.vpp.jvpp.core.dto.DhcpProxyDump;
 import io.fd.vpp.jvpp.core.future.FutureJVppCore;
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 import java.util.concurrent.CompletionStage;
@@ -47,6 +48,7 @@ import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.dhcp
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.dhcp.rev170315.dhcp.attributes.relays.Relay;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.dhcp.rev170315.dhcp.attributes.relays.RelayBuilder;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.dhcp.rev170315.dhcp.attributes.relays.RelayKey;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.dhcp.rev170315.relay.attributes.ServerBuilder;
 import org.opendaylight.yangtools.concepts.Builder;
 import org.opendaylight.yangtools.yang.binding.DataObject;
 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
@@ -72,10 +74,10 @@ final class DhcpRelayCustomizer extends FutureJVppCustomizer
 
             final CompletionStage<DhcpProxyDetailsReplyDump> result = getFutureJVpp().dhcpProxyDump(new DhcpProxyDump())
                 .thenCombine(getFutureJVpp().dhcpProxyDump(request),
-                (ip4, ip6) -> {
-                    ip4.dhcpProxyDetails.addAll(ip6.dhcpProxyDetails);
-                    return ip4;
-                });
+                    (ip4, ip6) -> {
+                        ip4.dhcpProxyDetails.addAll(ip6.dhcpProxyDetails);
+                        return ip4;
+                    });
             return getReplyForRead(result.toCompletableFuture(), id);
         };
     }
@@ -136,8 +138,14 @@ final class DhcpRelayCustomizer extends FutureJVppCustomizer
             builder.setRxVrfId(key.getRxVrfId());
             final boolean isIp6 = byteToBoolean(detail.isIpv6);
             builder.setGatewayAddress(readAddress(detail.dhcpSrcAddress, isIp6));
-            builder.setServerAddress(readAddress(detail.dhcpServer, isIp6));
-            builder.setServerVrfId(UnsignedInts.toLong(detail.serverVrfId));
+            if (detail.servers != null) {
+                builder.setServer(Arrays.stream(detail.servers).map(
+                    server -> new ServerBuilder()
+                        .setAddress(readAddress(server.dhcpServer, isIp6))
+                        .setVrfId(UnsignedInts.toLong(server.serverVrfId))
+                        .build()
+                ).collect(Collectors.toList()));
+            }
         }
     }
 
diff --git a/dhcp/dhcp-impl/src/main/java/io/fd/hc2vpp/dhcp/write/DhcpRelayCustomizer.java b/dhcp/dhcp-impl/src/main/java/io/fd/hc2vpp/dhcp/write/DhcpRelayCustomizer.java
index 58e3d5811..cb9939228 100644
--- a/dhcp/dhcp-impl/src/main/java/io/fd/hc2vpp/dhcp/write/DhcpRelayCustomizer.java
+++ b/dhcp/dhcp-impl/src/main/java/io/fd/hc2vpp/dhcp/write/DhcpRelayCustomizer.java
@@ -16,6 +16,8 @@
 
 package io.fd.hc2vpp.dhcp.write;
 
+import static com.google.common.base.Preconditions.checkArgument;
+
 import io.fd.hc2vpp.common.translate.util.ByteDataTranslator;
 import io.fd.hc2vpp.common.translate.util.FutureJVppCustomizer;
 import io.fd.hc2vpp.common.translate.util.Ipv4Translator;
@@ -26,11 +28,13 @@ import io.fd.honeycomb.translate.write.WriteContext;
 import io.fd.honeycomb.translate.write.WriteFailedException;
 import io.fd.vpp.jvpp.core.dto.DhcpProxyConfig;
 import io.fd.vpp.jvpp.core.future.FutureJVppCore;
+import java.util.List;
 import javax.annotation.Nonnull;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.IpAddress;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.dhcp.rev170315.Ipv6;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.dhcp.rev170315.dhcp.attributes.relays.Relay;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.dhcp.rev170315.dhcp.attributes.relays.RelayKey;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.dhcp.rev170315.relay.attributes.Server;
 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -47,7 +51,10 @@ final class DhcpRelayCustomizer extends FutureJVppCustomizer implements ListWrit
     public void writeCurrentAttributes(@Nonnull final InstanceIdentifier<Relay> id, @Nonnull final Relay dataAfter,
                                        @Nonnull final WriteContext writeContext) throws WriteFailedException {
         LOG.debug("Writing Relay {} dataAfter={}", id, dataAfter);
-        setRelay(id, dataAfter, writeContext, true);
+        checkArgument(dataAfter.getServer() != null && !dataAfter.getServer().isEmpty(), "At least one DHCP server needs to be configured");
+        for (final Server server : dataAfter.getServer()) {
+            setRelay(id, dataAfter, server, true);
+        }
     }
 
     @Override
@@ -55,26 +62,50 @@ final class DhcpRelayCustomizer extends FutureJVppCustomizer implements ListWrit
                                         @Nonnull final Relay dataAfter, @Nonnull final WriteContext writeContext)
         throws WriteFailedException {
         LOG.debug("Updating Relay {} before={} after={}", id, dataBefore, dataAfter);
-        setRelay(id, dataAfter, writeContext, true);
+        final List<Server> serversBefore = dataBefore.getServer();
+        checkArgument(serversBefore != null && !serversBefore.isEmpty(),
+            "At least one DHCP server needs to be configured before update operation");
+        final List<Server> serversAfter = dataAfter.getServer();
+        checkArgument(serversAfter != null && !serversAfter.isEmpty(),
+            "At least one DHCP server needs to be configured after update operation");
+
+        // remove old servers (we do not expect many, so no need for efficient search):
+        for (final Server server : serversBefore) {
+            if (!serversAfter.contains(server)) {
+                setRelay(id, dataAfter, server, false);
+            }
+        }
+        // and add new ones:
+        for (final Server server : serversAfter) {
+            if (!serversBefore.contains(server)) {
+                setRelay(id, dataAfter, server, true);
+            }
+        }
     }
 
     @Override
     public void deleteCurrentAttributes(@Nonnull final InstanceIdentifier<Relay> id, @Nonnull final Relay dataBefore,
                                         @Nonnull final WriteContext writeContext) throws WriteFailedException {
         LOG.debug("Removing Relay {} dataBefore={}", id, dataBefore);
-        setRelay(id, dataBefore, writeContext, false);
+        checkArgument(dataBefore.getServer() != null && !dataBefore.getServer().isEmpty(),
+            "At least one DHCP server needs to be configured");
+        for (final Server server : dataBefore.getServer()) {
+            setRelay(id, dataBefore, server, false);
+        }
     }
 
-    private void setRelay(final InstanceIdentifier<Relay> id, final Relay relay, final WriteContext writeContext,
-                          final boolean isAdd) throws WriteFailedException {
+    private void setRelay(final InstanceIdentifier<Relay> id, final Relay relay, final Server server,
+                          final boolean isAdd)
+        throws WriteFailedException {
         final DhcpProxyConfig request = new DhcpProxyConfig();
         request.rxVrfId = relay.getRxVrfId().byteValue();
         final boolean isIpv6 = Ipv6.class == relay.getAddressType();
         request.isIpv6 = booleanToByte(isIpv6);
-        request.serverVrfId = relay.getServerVrfId().intValue();
+        request.serverVrfId = server.getVrfId().intValue();
         request.isAdd = booleanToByte(isAdd);
-        request.dhcpServer = parseAddress(relay.getServerAddress(), isIpv6);
+        request.dhcpServer = parseAddress(server.getAddress(), isIpv6);
         request.dhcpSrcAddress = parseAddress(relay.getGatewayAddress(), isIpv6);
+        LOG.debug("DHCP config change id={} request={}", id, request);
         getReplyForWrite(getFutureJVpp().dhcpProxyConfig(request).toCompletableFuture(), id);
     }
 
diff --git a/dhcp/dhcp-impl/src/main/java/io/fd/hc2vpp/dhcp/write/DhcpWriterFactory.java b/dhcp/dhcp-impl/src/main/java/io/fd/hc2vpp/dhcp/write/DhcpWriterFactory.java
index 93dc8048e..062826aaf 100644
--- a/dhcp/dhcp-impl/src/main/java/io/fd/hc2vpp/dhcp/write/DhcpWriterFactory.java
+++ b/dhcp/dhcp-impl/src/main/java/io/fd/hc2vpp/dhcp/write/DhcpWriterFactory.java
@@ -16,6 +16,7 @@
 
 package io.fd.hc2vpp.dhcp.write;
 
+import com.google.common.collect.ImmutableSet;
 import com.google.inject.Inject;
 import io.fd.honeycomb.translate.impl.write.GenericListWriter;
 import io.fd.honeycomb.translate.write.WriterFactory;
@@ -25,6 +26,7 @@ import javax.annotation.Nonnull;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.dhcp.rev170315.Dhcp;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.dhcp.rev170315.dhcp.attributes.Relays;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.dhcp.rev170315.dhcp.attributes.relays.Relay;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.dhcp.rev170315.relay.attributes.Server;
 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
 
 /**
@@ -32,13 +34,17 @@ import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
  */
 public final class DhcpWriterFactory implements WriterFactory {
 
-    private static final InstanceIdentifier<Relay> RELAY_ID = InstanceIdentifier.create(Dhcp.class).child(Relays.class).child(Relay.class);
+    private static final InstanceIdentifier<Relay> RELAY_ID =
+        InstanceIdentifier.create(Dhcp.class).child(Relays.class).child(Relay.class);
 
     @Inject
     private FutureJVppCore vppApi;
 
     @Override
     public void init(@Nonnull final ModifiableWriterRegistryBuilder registry) {
-        registry.add(new GenericListWriter<>(RELAY_ID, new DhcpRelayCustomizer(vppApi)));
+        registry.subtreeAdd(
+            ImmutableSet.of(InstanceIdentifier.create(Relay.class).child(Server.class)),
+            new GenericListWriter<>(RELAY_ID, new DhcpRelayCustomizer(vppApi))
+        );
     }
 }
diff --git a/dhcp/dhcp-impl/src/test/java/io/fd/hc2vpp/dhcp/read/DhcpRelayCustomizerTest.java b/dhcp/dhcp-impl/src/test/java/io/fd/hc2vpp/dhcp/read/DhcpRelayCustomizerTest.java
index 79a1f44c8..0a64dd880 100644
--- a/dhcp/dhcp-impl/src/test/java/io/fd/hc2vpp/dhcp/read/DhcpRelayCustomizerTest.java
+++ b/dhcp/dhcp-impl/src/test/java/io/fd/hc2vpp/dhcp/read/DhcpRelayCustomizerTest.java
@@ -28,6 +28,7 @@ import io.fd.honeycomb.translate.spi.read.ReaderCustomizer;
 import io.fd.vpp.jvpp.core.dto.DhcpProxyDetails;
 import io.fd.vpp.jvpp.core.dto.DhcpProxyDetailsReplyDump;
 import io.fd.vpp.jvpp.core.dto.DhcpProxyDump;
+import io.fd.vpp.jvpp.core.types.DhcpServer;
 import java.util.List;
 import org.junit.Test;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.dhcp.rev170315.Dhcp;
@@ -38,19 +39,20 @@ import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.dhcp
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.dhcp.rev170315.dhcp.attributes.relays.Relay;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.dhcp.rev170315.dhcp.attributes.relays.RelayBuilder;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.dhcp.rev170315.dhcp.attributes.relays.RelayKey;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.dhcp.rev170315.relay.attributes.Server;
 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
 import org.opendaylight.yangtools.yang.binding.KeyedInstanceIdentifier;
 
 public class DhcpRelayCustomizerTest extends InitializingListReaderCustomizerTest<Relay, RelayKey, RelayBuilder> {
+    private static InstanceIdentifier<Relays> RELAYS = InstanceIdentifier.create(Dhcp.class).child(Relays.class);
+    private KeyedInstanceIdentifier<Relay, RelayKey> IP4_IID =
+        RELAYS.child(Relay.class, new RelayKey(Ipv4.class, 123L));
+    private KeyedInstanceIdentifier<Relay, RelayKey> IP6_IID =
+        RELAYS.child(Relay.class, new RelayKey(Ipv6.class, 321L));
     public DhcpRelayCustomizerTest() {
         super(Relay.class, RelaysBuilder.class);
     }
 
-    private static InstanceIdentifier<Relays> RELAYS = InstanceIdentifier.create(Dhcp.class).child(Relays.class);
-
-    private KeyedInstanceIdentifier<Relay, RelayKey> IP4_IID = RELAYS.child(Relay.class, new RelayKey(Ipv4.class, 123L));
-    private KeyedInstanceIdentifier<Relay, RelayKey> IP6_IID = RELAYS.child(Relay.class, new RelayKey(Ipv6.class, 321L));
-
     @Override
     protected ReaderCustomizer<Relay, RelayBuilder> initCustomizer() {
         return new DhcpRelayCustomizer(api);
@@ -61,9 +63,14 @@ public class DhcpRelayCustomizerTest extends InitializingListReaderCustomizerTes
         final DhcpProxyDetailsReplyDump ip4 = new DhcpProxyDetailsReplyDump();
         final DhcpProxyDetails ip4Proxy = new DhcpProxyDetails();
         ip4Proxy.rxVrfId = 123;
-        ip4Proxy.dhcpSrcAddress = new byte[]{1,2,3,4};
-        ip4Proxy.serverVrfId = 11;
-        ip4Proxy.dhcpServer = new byte[]{8,8,8,8};
+        ip4Proxy.dhcpSrcAddress = new byte[] {1, 2, 3, 4};
+        final DhcpServer ip4server1 = new DhcpServer();
+        ip4server1.serverVrfId = 11;
+        ip4server1.dhcpServer = new byte[] {8, 8, 8, 8};
+        final DhcpServer ip4server2 = new DhcpServer();
+        ip4server2.serverVrfId = 12;
+        ip4server2.dhcpServer = new byte[] {8, 8, 8, 4};
+        ip4Proxy.servers = new DhcpServer[] {ip4server1, ip4server2};
         ip4.dhcpProxyDetails.add(ip4Proxy);
         when(api.dhcpProxyDump(new DhcpProxyDump())).thenReturn(future(ip4));
 
@@ -71,12 +78,15 @@ public class DhcpRelayCustomizerTest extends InitializingListReaderCustomizerTes
         final DhcpProxyDetails ip6Proxy = new DhcpProxyDetails();
         ip6Proxy.rxVrfId = 321;
         // 2001:0db8:0a0b:12f0:0000:0000:0000:0001
-        ip6Proxy.dhcpSrcAddress = new byte[] {0x20, 0x01, 0x0d, (byte) 0xb8, 0x0a, 0x0b, 0x12, (byte) 0xf0, 0 ,0 ,0 ,0 ,0 ,0 ,0 ,0x01};
-        ip6Proxy.serverVrfId = 22;
-        ip6Proxy.isIpv6  = 1;
+        ip6Proxy.dhcpSrcAddress =
+            new byte[] {0x20, 0x01, 0x0d, (byte) 0xb8, 0x0a, 0x0b, 0x12, (byte) 0xf0, 0, 0, 0, 0, 0, 0, 0, 0x01};
+        final DhcpServer ip6server = new DhcpServer();
+        ip6server.serverVrfId = 22;
         // 2001:0db8:0a0b:12f0:0000:0000:0000:0002
-        ip6Proxy.dhcpServer = new byte[] {0x20, 0x01, 0x0d, (byte) 0xb8, 0x0a, 0x0b, 0x12, (byte) 0xf0, 0 ,0 ,0 ,0 ,0 ,0 ,0 ,0x02};
-
+        ip6server.dhcpServer =
+            new byte[] {0x20, 0x01, 0x0d, (byte) 0xb8, 0x0a, 0x0b, 0x12, (byte) 0xf0, 0, 0, 0, 0, 0, 0, 0, 0x02};
+        ip6Proxy.servers = new DhcpServer[] {ip6server};
+        ip6Proxy.isIpv6 = 1;
         final DhcpProxyDump ip6Dump = new DhcpProxyDump();
         ip6Dump.isIp6 = 1;
         ip6.dhcpProxyDetails.add(ip6Proxy);
@@ -96,9 +106,13 @@ public class DhcpRelayCustomizerTest extends InitializingListReaderCustomizerTes
         getCustomizer().readCurrentAttributes(IP4_IID, builder, ctx);
         assertEquals(IP4_IID.getKey().getAddressType(), builder.getAddressType());
         assertEquals(IP4_IID.getKey().getRxVrfId(), builder.getRxVrfId());
-        assertEquals(11L, builder.getServerVrfId().longValue());
         assertArrayEquals("1.2.3.4".toCharArray(), builder.getGatewayAddress().getValue());
-        assertArrayEquals("8.8.8.8".toCharArray(), builder.getServerAddress().getValue());
+        final List<Server> server = builder.getServer();
+        assertEquals(2, server.size());
+        assertEquals(11L, server.get(0).getVrfId().longValue());
+        assertArrayEquals("8.8.8.8".toCharArray(), server.get(0).getAddress().getValue());
+        assertEquals(12L, server.get(1).getVrfId().longValue());
+        assertArrayEquals("8.8.8.4".toCharArray(), server.get(1).getAddress().getValue());
     }
 
     @Test
@@ -107,9 +121,9 @@ public class DhcpRelayCustomizerTest extends InitializingListReaderCustomizerTes
         getCustomizer().readCurrentAttributes(IP6_IID, builder, ctx);
         assertEquals(IP6_IID.getKey().getAddressType(), builder.getAddressType());
         assertEquals(IP6_IID.getKey().getRxVrfId(), builder.getRxVrfId());
-        assertEquals(22L, builder.getServerVrfId().longValue());
+        assertEquals(22L, builder.getServer().get(0).getVrfId().longValue());
         assertArrayEquals("2001:db8:a0b:12f0::1".toCharArray(), builder.getGatewayAddress().getValue());
-        assertArrayEquals("2001:db8:a0b:12f0::2".toCharArray(), builder.getServerAddress().getValue());
+        assertArrayEquals("2001:db8:a0b:12f0::2".toCharArray(), builder.getServer().get(0).getAddress().getValue());
     }
 
     @Test
diff --git a/dhcp/dhcp-impl/src/test/java/io/fd/hc2vpp/dhcp/write/DhcpRelayCustomizerTest.java b/dhcp/dhcp-impl/src/test/java/io/fd/hc2vpp/dhcp/write/DhcpRelayCustomizerTest.java
index d13990c7a..a6a407ae4 100644
--- a/dhcp/dhcp-impl/src/test/java/io/fd/hc2vpp/dhcp/write/DhcpRelayCustomizerTest.java
+++ b/dhcp/dhcp-impl/src/test/java/io/fd/hc2vpp/dhcp/write/DhcpRelayCustomizerTest.java
@@ -17,7 +17,6 @@
 package io.fd.hc2vpp.dhcp.write;
 
 import static org.mockito.ArgumentMatchers.any;
-import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
@@ -43,7 +42,8 @@ import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
 public class DhcpRelayCustomizerTest extends WriterCustomizerTest implements SchemaContextTestHelper {
 
     private static final String RELAYS_PATH = "/dhcp:dhcp/dhcp:relays";
-    private static final InstanceIdentifier<Relays> RELAYS_IID = InstanceIdentifier.create(Dhcp.class).child(Relays.class);
+    private static final InstanceIdentifier<Relays> RELAYS_IID =
+        InstanceIdentifier.create(Dhcp.class).child(Relays.class);
 
     private DhcpRelayCustomizer customizer;
 
@@ -63,24 +63,29 @@ public class DhcpRelayCustomizerTest extends WriterCustomizerTest implements Sch
         request.rxVrfId = rxVrfId;
         request.isIpv6 = 0;
         request.isAdd = 1;
-        request.dhcpServer = new byte[]{1,2,3,4};
-        request.dhcpSrcAddress = new byte[]{5,6,7,8};
+        request.dhcpServer = new byte[] {1, 2, 3, 4};
+        request.dhcpSrcAddress = new byte[] {5, 6, 7, 8};
+        verify(api).dhcpProxyConfig(request);
+        request.dhcpServer = new byte[] {1, 2, 3, 5};
         verify(api).dhcpProxyConfig(request);
     }
 
     @Test
-    public void testUpdate(@InjectTestData(resourcePath = "/relay/ipv6DhcpRelay.json", id = RELAYS_PATH) Relays relays)
+    public void testUpdate(
+        @InjectTestData(resourcePath = "/relay/ipv6DhcpRelayBefore.json", id = RELAYS_PATH) Relays relaysBefore,
+        @InjectTestData(resourcePath = "/relay/ipv6DhcpRelayAfter.json", id = RELAYS_PATH) Relays relayAfter)
         throws WriteFailedException {
-        final Relay data = relays.getRelay().get(0);
+        final Relay before = relaysBefore.getRelay().get(0);
+        final Relay after = relayAfter.getRelay().get(0);
         final int rxVrfId = 1;
-        customizer.updateCurrentAttributes(getId(rxVrfId, Ipv6.class), mock(Relay.class), data, writeContext);
+        customizer.updateCurrentAttributes(getId(rxVrfId, Ipv6.class), before, after, writeContext);
         final DhcpProxyConfig request = new DhcpProxyConfig();
         request.rxVrfId = rxVrfId;
         request.serverVrfId = 2;
         request.isIpv6 = 1;
-        request.isAdd = 1;
-        request.dhcpServer = new byte[]{0x20, 0x01, 0, 0, 0, 0, 0, 0, 0 ,0 ,0 ,0 ,0 ,0 ,0 ,0x01};
-        request.dhcpSrcAddress = new byte[]{0x20, 0x01, 0, 0, 0, 0, 0, 0, 0 ,0 ,0 ,0 ,0 ,0 ,0 ,0x02};
+        request.isAdd = 0;
+        request.dhcpServer = new byte[] {0x20, 0x01, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x01};
+        request.dhcpSrcAddress = new byte[] {0x20, 0x01, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x02};
         verify(api).dhcpProxyConfig(request);
     }
 
@@ -94,8 +99,10 @@ public class DhcpRelayCustomizerTest extends WriterCustomizerTest implements Sch
         request.rxVrfId = rxVrfId;
         request.isIpv6 = 0;
         request.isAdd = 0;
-        request.dhcpServer = new byte[]{1,2,3,4};
-        request.dhcpSrcAddress = new byte[]{5,6,7,8};
+        request.dhcpServer = new byte[] {1, 2, 3, 4};
+        request.dhcpSrcAddress = new byte[] {5, 6, 7, 8};
+        verify(api).dhcpProxyConfig(request);
+        request.dhcpServer = new byte[] {1, 2, 3, 5};
         verify(api).dhcpProxyConfig(request);
     }
 
diff --git a/dhcp/dhcp-impl/src/test/resources/relay/ipv4DhcpRelay.json b/dhcp/dhcp-impl/src/test/resources/relay/ipv4DhcpRelay.json
index 27550e45f..2c7dda289 100644
--- a/dhcp/dhcp-impl/src/test/resources/relay/ipv4DhcpRelay.json
+++ b/dhcp/dhcp-impl/src/test/resources/relay/ipv4DhcpRelay.json
@@ -4,8 +4,17 @@
       {
         "address-type": "ipv4",
         "rx-vrf-id": 0,
-        "server-address": "1.2.3.4",
-        "gateway-address": "5.6.7.8"
+        "gateway-address": "5.6.7.8",
+        "server" : [
+          {
+            "vrf-id": 0,
+            "address": "1.2.3.4"
+          },
+          {
+            "vrf-id": 0,
+            "address": "1.2.3.5"
+          }
+        ]
       }
     ]
   }
diff --git a/dhcp/dhcp-impl/src/test/resources/relay/ipv6DhcpRelay.json b/dhcp/dhcp-impl/src/test/resources/relay/ipv6DhcpRelay.json
deleted file mode 100644
index ca7e51ace..000000000
--- a/dhcp/dhcp-impl/src/test/resources/relay/ipv6DhcpRelay.json
+++ /dev/null
@@ -1,13 +0,0 @@
-{
-  "relays": {
-    "relay": [
-      {
-        "address-type": "ipv6",
-        "rx-vrf-id": 1,
-        "server-address": "2001::1",
-        "server-vrf-id": 2,
-        "gateway-address": "2001::2"
-      }
-    ]
-  }
-}
diff --git a/dhcp/dhcp-impl/src/test/resources/relay/ipv6DhcpRelayAfter.json b/dhcp/dhcp-impl/src/test/resources/relay/ipv6DhcpRelayAfter.json
new file mode 100644
index 000000000..7c2518b54
--- /dev/null
+++ b/dhcp/dhcp-impl/src/test/resources/relay/ipv6DhcpRelayAfter.json
@@ -0,0 +1,17 @@
+{
+  "relays": {
+    "relay": [
+      {
+        "address-type": "ipv6",
+        "rx-vrf-id": 1,
+        "gateway-address": "2001::2",
+        "server" : [
+          {
+            "vrf-id": 2,
+            "address": "2001::10"
+          }
+        ]
+      }
+    ]
+  }
+}
diff --git a/dhcp/dhcp-impl/src/test/resources/relay/ipv6DhcpRelayBefore.json b/dhcp/dhcp-impl/src/test/resources/relay/ipv6DhcpRelayBefore.json
new file mode 100644
index 000000000..94f7c6558
--- /dev/null
+++ b/dhcp/dhcp-impl/src/test/resources/relay/ipv6DhcpRelayBefore.json
@@ -0,0 +1,21 @@
+{
+  "relays": {
+    "relay": [
+      {
+        "address-type": "ipv6",
+        "rx-vrf-id": 1,
+        "gateway-address": "2001::2",
+        "server" : [
+          {
+            "vrf-id": 2,
+            "address": "2001::1"
+          },
+          {
+            "vrf-id": 2,
+            "address": "2001::10"
+          }
+        ]
+      }
+    ]
+  }
+}